Intermittent MFD display fixed with cleaning circuit board connection.

[northwichita]

My 04 prius with 158k started having more frequent MFD display problems. For a week, the initial start up would be a problem, i.e. check a/c connection on climate screen, slow screen toggles, no input for energy bars ect. This would last a minute, and then work fine, until about an hour later, when it would relapse, I would know this occurred by the radio changing channels , and screen would go to slow mode for about a minute, then work. I have first noticed this screen problem about 6 months ago, rarely (monthly ?), then recently daily.
Most of web searches point to Hobbits web writeup describing the solution to be a very small solder repair,
Prius MFD
My MFD is the same as the write-up in this link model 47080 non-navigational.
As my problem was intermittent, I leaned more toward an internal connection problem, thinking a partial break wouldn't last as long with the gravel roads I drive on and I have had problems with the dust in window switches etc. I did read that Hobbit first checked and cleaned connections and used DeOxIt, so I decided to try that.
I took out the MFD following this site
Prius MFD Touchscreen Repair
note the MFD is connected with a wire to the bezel, which is the plastic front, the white wire connection simply pries apart with a small screwdriver .
Once free, I took the MFD on a table, took off the back cover and side metal cover. There are four screws holding on the back circuit board, plus two small wire bundles connecting the boards which pryed apart at the bases, aside from the main connector which I cleaned . Sorry took no pic's.

I briefly looked for a bad solder point, did not see one, but was impressed by how small everything was. I sprayed the main connection for the two circuit boards with electrical spray from Radio Shack. I bought the best spray they had. DeoxIt/ProGold twin pack. DeoxIT™/ProGold™ Twin Pack - RadioShack.com
I sprayed on either side of the connection for the two circuit boards, dried, reassembled, and the screen has worked fine on start-up and for the rest of the week.

I do not have much electrical training or familiarity with board circuitry, and am writing this up to show a possible easy fix the MFD display problem , especially the intermittent ones. I wouldn't think cleaning a connection would prevent trade-in for repair if it doesn't fix the problem. Now that the unit is working I regret not taking some photo's, but really don't want to disassemble it while its working well. There is always next time.

Again thank you Hobbit for the inspiration, instructions and pic's to lead me to do this, I had fun and saved some bucks.

[richard schumacher]

Dust? Do you not use A/C recirc very much?

[northwichita]

Originally Posted by richard schumacher

Dust? Do you not use A/C recirc very much?

I'm a rural mail carrier, driving over 100 miles of gravel roads a day with the right window down. I blow the dust out the cabin air filter monthly. Dust may have played a role in my MFD problem, I thought of wrapping the unit with plastic, but didn't, because of the heat buildup. I did put some plastic right above the rear wire bundle connector going into the unit. I forgot to mention I did clean that connection first, but had no improvement, so took the MFD apart.
I looked into electric conductive pastes that would better seal off the connection , but assume they may just cause more problems if I use to much, and most refer to aluminum, which doesn't apply here.


Found a priuschat page further describing dash panel removal (an 08), the more info the better,right?
Radio Removal Tips With Pictures

[fatdawg]

northwichita, is your MFD still working? let me know, I am having the same intermittent problems and I would like to try your fix this weekend...

[fatdawg]

I did this tonight and my navigation / mfd is now working! The tear down, cleanup, and re-install took under 2 hours. The components are ridicoulously small, I would have had to spend good money for a good soldering iron. The DeoxIT / ProGold kit from radioshack worked great for $15.00!

thanks again!

[ceric]

I wish you the best of luck.
Keep your fingers crossed.

[northwichita]

Three weeks and 2,500 miles later in dusty conditions, my MFD works fine. I usually do have the screen on 'off', but I can tell its not 'acting up' because the radio doesn't change stations at strange times and it turns on when needed. Glad to have helped.

update 10/20/09 mine is still working normally. Reading other posts, everyone else who tried this has had limited success, that is three other people were helped,including fatdawg , then the problem came back for them. Post if you've had success. Will update here from time to time.

11/12/09 Prius is starting to act up again!!!!!!!!! GR.. It works, just on start up it will no work, then will be okay, seems to be a cold and wet-was a rainy day- related function, though this is how it started last time. Probably will try something, retry cleaning maybe. 163 k miles.
Next two days, nothing wrong, so I'll see how long it works. It is dryer, it acted up on a very humid day.